In conventional photography, the camera must typically be focused at the time the photograph is taken. The resulting image may have only color data for each pixel; accordingly, any object that was not in focus when the photograph was taken cannot be brought into sharper focus because the necessary data does not reside in the image.
By contrast, light-field images typically encode additional data for each pixel related to the trajectory of light rays incident to that pixel when the light-field image was taken. This data can be used to manipulate the light-field image through the use of a wide variety of rendering techniques that are not possible to perform with a conventional photograph. In some implementations, a light-field image may be refocused and/or altered to simulate a change in the center of perspective (CoP) of the camera that received the image. Further, a light-field image may be used to generate an enhanced depth-of-field (EDOF) image in which all parts of the image are in focus. A depth map can typically be obtained from a light-field image, indicating the depth at which objects in the light-field image were disposed, relative to the light-field camera, at the time the light-field image was captured.
Existing techniques for processing conventional images are limited in many respects. Specifically, editing conventional images to provide effects, such as changing colorization, contrast, or objects in the image, can be challenging. Typically, the user must employ careful selection of object boundaries to control how the effects are applied. Accordingly, application of effects in conventional images can be a time-consuming and labor-intensive effort. Existing processing and effect application techniques for light-field images often do not make full use of the information in the light-field image, or utilize a user interface that makes it difficult for the user to locate and apply the desired effect.